1. Field of the Invention
This invention relates generally to an article coding and separating system, and in particular to one adapted for egg candling. The system is disclosed herein in the form of an improved egg candler which is suitable for identifying defects such as blood spots, dirt stains, rough spots and shell cracks during an egg grading process and may also be utilized in coding other articles on a moving conveyor for diversion at a point downstream.
2. Description of the Prior Art
Systems for sorting articles and separating defective articles from the mass of articles being conveyed are known. One such system is disclosed in U.S. Pat. No. 4,164,291 for a "Sorting Apparatus" and is designed to separate undesirable materials such as stones from potatoes being harvested. The patented apparatus provides a matrix or sets of orthogonal coils for receiving electrical signals transmitted by a selector member. The orthogonal coils are arranged to define an array of sites, the coils being thus disposd in a matrix beneath the conveyor which carries the potatoes being processed. A selector member or wand is provided for hand operation by an operator whose function is to conduct a visual inspection of the material on the conveyor. The selector member is in the form of a rod-like member adapted to be hand-held by the operator and includes a piezoelectric transducer which emits bursts of a radio frequency electro-magnetic signal. The selector member or wand is activated upon contact with the object selected by the operator as an object to be rejected.
The system disclosed in U.S. Pat. No. 4,164,291 includes a multiplicity of parts, particularly in forming the matrix of coils employed therein. Moreover, this system is designed to identify only the location of articles and does not have the capability of also identifying the particular physical characteristics of the article which is considered to be undesirable or a defect.
In addition, while the patent indicates it is adapted for use with egg candlers, in such a system, the coils forming the grid therein would most probably interfere at least to some degree with the lighting necessary in the candling area. Egg candlers, generally speaking, consist of a movable conveyor including a plurality of spool bars disposed in aligned, spaced-apart relationship which conveys eggs over a high-intensity light source to enable the visual detection of a variety of possible defects such as blood spots, dirt stains, rough spots, shell cracks and the like. Such egg candlers may be used either alone or in combination with an egg grader for classifying and separating eggs according to their individual physical characteristics, including weight.
In such egg candlers, there are limitations on the operational speed of the machine, which in turn limit the maximum operating speed for an entire automated egg processing system. In order to improve the operating efficiency of such egg processing systems, the speed at which defective eggs are detected and defects are identified by the candler must be increased. This requires a candler which has a high-speed response time but which also enables accurate identification and separation of defective eggs. The detection of eggs having defects is of utmost importance since oversights would result in the packaging of eggs which do not conform to government specifications. Thus, the candling function must be carried out at a speed which is low enough to enable accurate and complete visual detection of defects as the eggs are conveyed through the candler, yet at a speed which is rapid enough so as not to limit the maximum operational speed of the processing system with which the candler is used. Inevitably, this places increased performance demands on the egg candler.